family Compositae vs genus Dahlia

family Compositae and genus Dahlia both are nouns.

Word	Noun	Adjective	Verb	Adverb
family Compositae	Yes	No	No	No
genus Dahlia	Yes	No	No	No

family Compositae (noun)	genus Dahlia (noun)
plants with heads composed of many florets: aster, daisy, dandelion, goldenrod, marigold, lettuces, ragweed, sunflower, thistle, zinnia	genus of perennial tuberous plants of Mexico and Central America